WO1990015690A2 - Machine-tools for the machining of complex globular shapes - Google Patents

Abstract

Machine tools for the machining of complex globular shapes designed for the manufacture of parts with evolutive configurations. The part to be machined, which is placed on a support (K) is contoured by the tool (G) which is held by a mechanical assembly. Said assembly includes two arms (L) and (M) whose rotation axles (O O) and (Q Q) are each set at 90° in relation to other, and have a common intersection point (I) corresponding to the tool head (G). The assembly also includes a linear axle (P P) perpendicular to the rotation axle of the arm (L) and integral to same, said linear axle also passing through the common intersection point of the two arms (L) and (M). The support (K) may rotate, in a controlled manner, around an axle (R R). The part and the tool (G) may equally be moved, in a complementary manner through 1, 2, or 3 axes (X, Y, Z). The production of complex shapes is considerably facilitated by the fact that the axles are extremely free, which enables the machining of prototype shapes for vanes, or for new artistic shapes, to take place.

Description

 Machine tools for machining complex global shapes.

 The present invention relates to a machine tool intended for the manufacture and machining of evolving complex shapes which can be located around an axis of rotation.

 Conventional machines, milling machines, planers, boring machines, etc. have been receiving tools for a long time allowing them to orient tools, milling cutters, knives, etc. in order to try to obtain the optimum position to promote cutting of the tool and realize the dimensional isbic characteristics 1 es sought. This is very difficult when the shapes to be machined move in all directions.

 The universally known "Huré" type strawberry orientation head and the various selected patents cited below, clearly demonstrate the work carried out in this area.

U.S. Patent 2,794,371 6/4/57 shows the principle

geometric of the machining on the tip of the tool on a flat surface with clearance in 2 directions

perpendicular areas.

 Patent F.R. 2,158,077 10/26/71 shows the real i sati on of a milling head which can be oriented on the tip of the tool with complementary pivoting arms arranged at 45 °.

 U.S. Patent 2,784,647 5/1/53 shows the addition of two complementary pivoting arms arranged at 98 °, but using two bearings placed on either side of the tool on the same axis. US Patent 3,483,796 06/14/68 shows 2 arms pivoting on axes at 90 ° with 2 bearings on an axis and a linear insertion axis disposed in the center which because of this arrangement is not intended to work at the point of intersection of the 2 axes at 90 °

Patent FR 1,602,333 30/12/68 shows a tool offset device by carriage allowing the tangent machining of said tool but which does not allow the offset over 368 °. In fact none of these machines has arms with freedom sufficient movement to allow almost entirely global spiral shapes to be produced without dismantling the workpiece.

 The machine of the present invention makes it possible to avoid

main disadvantages encountered and offers in particular thanks to. on the one hand, its 2 arms at 90 ° with a single bearing each, maximum clearance at the level of the mechanisms allowing optimum movement, without the risk of collision between the

tool supports and the workpiece support,

and on the other hand the complementary complementary linear axis moving around the point of intersection of the axes of rotation of the two arms (or tip of the tool) makes it possible to register drifts which would be difficult to control using only XYZ axes

 Finally, the offset of the tool with respect to its axis makes it possible to take account of its diameter and to make it work at its best with its tangent with respect to the surface to be machined.

-According to a first characteristic this machine, which has its movements controlled simultaneously, using as support on the workpiece side or on the tool side i ndi fferement, either a fixed point or the 1,2 or 3 conventional axes s X, Y, Z, comprising on the one hand a member for holding the workpiece, and on the other hand a tool G held by successive articulated support elements comprising on the one hand, 2 pivoting arms on axes arranged angularly in relation to one another to the other and around a common point of intersection, intended to machine the part during their movements and on the other hand a linear axis of depression, is remarkable in that -face to the axis RR of l the workpiece retaining member, coincides on the tool side G with an axis of rotation QQ, on which the point is located

intersection I located in the work area of the part and materializing the position of the tip of the tool G in space; the said axis of rotation QQ and the point I are at the intersection with a linear axis PP constituting the driving-in axis, crossing the axis of rotation QQ at normal, and driving in, crossing the axis of rotation QQ to normal, and in that the said linear axis PP at a point A forming a sliding guide is secured by an arm L to a rotation bearing B located on the axis QQ and opposite the member for holding the part with respect to the point of intersection I, the point A of the sliding guide of the arm L disposed on the axis PP being sufficiently spaced from the point of intersection I in order to be able to insert therein at least the body of the tool G and its support, - located on the axis QQ opposite to the holding member K of the part and a little further from the point of intersection I that the rotation bearing B, is a point C axially and longitudinally secured to the rotation bearing B supporting the second pivot arm M, from I and arranged perpendicular to the axis QQ and in the plane described by the axis linear PP when pivoted around B, there is an axis of rotation OO on which is located é a rotation bearing D secured to the arm M further from the point

of intersection I as the point of the sliding guide A of the arm L, and situated on the same side, the arm M being larger than the arm L, the said axis of rotation 0 0 being secured, either at a fixed point, or at least one of the three orthogonal axes X, Y, Z, so that the rotation of the arm L on the rotation bearing B of the axis QQ and the rotation of the arm M on the rotation bearing D of the axis OO, offset RR and QQ as well as PP and OO but have no effect on the position of the tip of the tool G with respect to the point of intersection I, in this way the so-called tip of the tool can be oriented in all directions that may emanate from point I, except for the area

neutralized by the presence of the holding member of the machine which supports the workpiece, while the

displacement of the support of the tool G on the axis P P and on one of the linear axes X, Y, Z, ensures that the tip of the tool G also moves and no longer coincides with the point

of intersection I, thus making it possible to machine other points located in space. -According to other characteristics, this machine of the type

comprising a rotary or stationary tool G having a circular part in section is remarkable by the fact that it includes an eccentric device E making it possible to offset the linear driving axis P P into P'P 'offset by a value

corresponding to the radius of said tool G, and in that said eccentricity device E is combined with a member for

displacement, motorized or not, so that the cutting of the tool

G is carried out at normal to the surface of the workpiece by the point of tangency of the tool.

 This machine is also remarkable in that the linear driving movement of the linear axis P P or P'P is carried out by a slide offset towards the plane of the bearing B.

 According to a preferred embodiment, when the axis OO is secured with at least one of the 3 conventional axes s X, Y, Z, or a fixed point on the tool side G, the different axes or the fixed point are supported by a rotat ion bearing J do nt the TT axis is co nf o ndu or parallel to the Z axis and arranged opposite the working point of the tool G with respect to the bearing D of so as to allow the axes X and Y to be oriented at all the desired angle values relative to the axis of the part holding member.

 According to another preferred embodiment, the member for holding the workpiece is provided with a recoil device N on the axis R R making it possible to release said part backwards away from the tool G.

 According to another particular feature, the machine control station is located between points I and B and the idari sation floor arm

L which connects the tool and its support to the rotation bearing B is shaped along its length so as to define a recess, so that sufficient space is provided for the operator of the machine and the control station therein. .

 According to a particular embodiment the rotation bearing

B, is deported to point C.

According to a final feature, the body for maintaining the part is rotat ed and co nst i killed by a doll placed on the RR axis and re li ected to m ave ns of mi se in rotat ion at mo uveme nt s

 checked.

 -The application of such a machine is especially oriented towards the creation of complex shapes of the "snail" type and can allow the manufacture of parts including surfaces and profiles

 require a tool orientation that is constantly controlled in all directions. The realization of complex shapes is greatly facilitated due to the greater freedom of the axes and allows the machining of prototype shapes for blades, or new artistic forms. The reasoning of the machine operator is facilitated by the split of the axial functions. The arrangement of the axes as described is not

limiting. The doubling or addition of axes on this basic arrangement, for example X, Y, Z to hold the tool, should be considered as extensions of the latter which is fundamental and cannot be opposed to it.

 This experimented arrangement reveals an optimum solution which cannot be diverted, for example, by making the bearings B and C rotating simultaneously.

 The tool can be of different designs: either rotary:

spindle with cutter for example, either static such as a heating knife etc. or even sophisticated such as laser, high frequency electrode, without this being limiting.

 The construction of the machine calls upon all the techniques currently known for slides, bearings, ball screws, roller screws, etc.

 The most suitable materials are used to respond to the problems of corrosion, bending, torsion, abrasion, etc.

 The motorization uses stepping motors, direct current, etc ...

 Measurement and control are carried out using encoders or rules, incremental or absolute, etc.

Safety devices avoid the risk of collision when approaching extreme or dangerous conditions when reaching

maximum travel.

 The entire machine is managed by a digital control.

 Drawings are attached which are given for information only and not limitative. This machine being "described with elements voluntarily schematized in order to better facilitate understanding.

 Reference will be made to the following drawings:

 Figure 1 is a schematic view of the various axes defining the operation of the machine in a privileged educational position.

 Figure 2 is a view with local section showing the eccentricity device.

 Figure 3 shows a complete machine with its

driver.

 FIG. 4 represents a support assembly for the part with rotational movement around the axis R R and reversing device N. Mounted on the axes X, Y, Z.

 With reference to these drawings, this machine is made up of different elements which, in a particular position, are stated as follows;

 -A support K maintains the workpiece on an axis R R. The latter is secured to a fixed point or to one of the three orthogonal axes X, Y, Z. A reversing device N allows the part to be released backwards for better

view or save it. The tip of the tool G is at the intersection I of the axes RR, PP, OO, and Q Q. The tool G with its tool holder is placed on a linear axis PP merged with the axis O O. The latter are perpendicular to the RR and QQ axes which are themselves combined. The tool G with its tool holder is connected by an arm L, fixed on one side with the point A of the axis PP and on the other side with the rotation bearing B placed on the axis Q Q. The rotation bearing B is secured to point C also placed on axis Q Q. This last point is even connected by another arm M to the rotation bearing D placed on the axis O O. The rotation bearing D is secured either with a fixed point or with one of the conventional axes X, Y, Z. This fixed point or one of the X, Y, Z axes is placed on a TT axis which may or may not coincide with the Z axis and held by a rotation bearing J. This makes it possible to orient the X and Y axes at any desired angle values relative to the workpiece holding member K. During operation the rotation of the arm L on the bearing B of the axis QQ and the rotation of the arm M on the rotation bearing D of the axis OO, misalign the axes RR and QQ as well as PP and O O. This does not affect the position of the tip of the tool G with respect to the point

of intersection I. The tool can therefore be oriented in all directions except for the area neutralized by the presence of the member K for holding the part. Any displacement on the axes P P or X, Y, Z, brings about a displacement of the point of the tool G with respect to the point of intersection I which no longer coincide. This therefore makes it possible to machine other points located in space.

To allow the offset of the tool G with respect to its axis P P when it is circular to the right of its section, an eccentricity device E is used. The axis PP is offset at P 'P' by a value corresponding to the radius of the tool G. In this way the tool G can work permanently with its best point of contact with the part, thus avoiding grooves and other appearance defects on machined surfaces. It also promotes dimensional qualities.

In a complete machine described for example, we find a frame H supporting the bearing J located on the axis TT which authorizes the rotation of the assembly on the tool side G. Then come the three axes X, Y, Z, the bearing D located on the axis 0 0, the arm M ensuring the connection with the point C located on the axis Q Q. The rotation bearing B, materially secured in length on the axis QQ with the point C, is secured with the linear axis PP by the arm L smaller than the arm M. The driving-in axis P 'P' is offset from the axis OO towards the plane of the bearing B. The device of eccentricity E allows to constantly optimize the efficiency of the point of attack of the tool G.

 The support K located on the axis R R makes it possible to present the part in the best possible way to ensure the desired machining.

This can be achieved through the X, Y, Z axes, supporting

possibly the axis R R which can be rotary. On the axis R R a reversing device N makes it possible to release the part of the tool to view it, save it, dismantle it, etc.

 The invention is in any case not limited to the embodiments described but covers, on the contrary, all the variants which could be made to them without departing from their scope or their spirit. All currently known techniques are used for the construction of such a machine.

It should therefore be recognized that, while retaining most of the general character of the machine described above, the

evolutions of forms which result from the conventional and instinctive laws of mechanical construction, will form part of the present invention.

 All construction techniques, whether foundry, mechanic welding, stamping, etc. are used for the construction of this machine. All metallic materials, plastics, composites, etc ... can be used.

 The application of the machine of the present invention relates to all complex forms whatever their final applications. The very difficult snail-like shapes are of course the first to be

 concerned.

Claims

REVENDI CAT IONS  1 °  TOOL MACHINE FOR THE MACHINING OF COMPLEX GLOBAL FORMS with simultaneously controlled movements, either as support on the workpiece side or on the tool side, either a fixed point or the 1,2 or 3 conventional axes s X, Y, Z, and comprising d on the one hand a member K for holding the workpiece, and on the other hand a tool G held by successive articulated support elements comprising on the one hand, 2 pivoting arms L and M on axes QQ and OO, l 'one M articulated around OO by a bearing D on the frame, the other L articulated around QQ by a bearing or point B maintained on said arm M by the bearing C and supporting the tool G, these axes being arranged perpendicular to each other and around a point of common intersection I materializing the position of the point of the tool in space, intended to machine the part during their movements and on the other hand a linear axis of depression PP arranged on the arm L, the assembly being made so that, facing the axis RR of the holding member K of the workpiece, is found to coincide on the tool side G, the axis of rotation QQ; characterized in that the driving-in axis P P crosses the axis of rotation Q Q to normal and includes a guide sliding A connecting the arm L and the tool G and its support, thus the displacement of the tool G on the axis PP causes the tip of the tool G to move and then no longer coincides with the point of intersection I thus making it possible to machine other points located in space. 2 °  Machine tool for the machining of complex global shapes according to claim 1 of the type comprising a rotary or fixed tool G having in section a circular part characterized in that it comprises an eccentric device E making it possible to offset the linear axis PP drive in P'P offset by a value corresponding to the radius of said tool G, and in that said eccentricity device E is combined with a displacement member, motorized or not, so that the cutting of tool G is carried out at normal to the surface of the workpiece by the point of tangency of the tool. Machine tool for machining complex global shapes, according to claim 1 or 2, characterized in that the linear movement of the linear axis P P or P'P is made by a slide offset to the plane of the bearing B. 4 °  Machine tool for machining complex global shapes, according to any one of the preceding claims in which the axis OO is secured to at least one of the 3 conventional axes s X, Y, Z, or a fixed point on the tool side G characterized in that the said axes or the fixed point are supported by a rotation bearing J whose axis TT is coincident or parallel to the axis Z and disposed opposite the working point of the tool G relative to bearing D so as to allow the axes X and Y to be oriented at all the angle values desired with respect to the axis of the part holding member. 5 °  Machine tool for the machining of complex global shapes, according to claim 1, characterized in that the member for holding the workpiece is provided with a recoil device N on the axis RR making it possible to release the said back piece opposite tool G. 6 ° Machine tool for machining complex global shapes, according to claim 1 or 3, characterized in that the machine control station is located between points I and B and that the idari sation arm L which connects the 'tool and its support to the rotation bearing B is shaped along its length so as to define a recess, so that sufficient space is provided to have the operator of the machine, and the control station. Machine tool for machining complex global shapes, according to claim 1, characterized in that the rotation bearing B is offset on the point or bearing C. 8 °  Machine tool for machining complex global shapes, according to any one of the preceding claims, carctèrisée in that the part holding member is rotatable and consists of a headstock placed on the axis R R and connected to means of rotation with controlled movements.